This invention relates to a toothbrush.
Dentists and other dental professionals have long recognized the advantages in applying a rotary motion to the bristles of a toothbrush when cleaning teeth such that the bristles move in a generally circular path across the surface of the teeth. This is particularly important in the region where the teeth protrude from the gum line.
It has been observed that the desired rotational action of the bristles can be difficult to achieve using conventional toothbrushes of the type having a head portion that is rigidly connected to a handle due to the size and configuration of both the toothbrush and the person""s mouth.
Attempts have been made to overcome the aforementioned problems by providing toothbrushes that have a head portion which is flexibly connected to the handle. However this still does not overcome the problem that rotational motion of the bristles can only be achieved by the user rotating the entire head portion inside the user""s mouth. This can be rather difficult and wherein generally speaking only the surfaces of some teeth can be cleaned in this manner, particularly if contact with the adjacent surfaces of the mouth are to be avoided.
Toothbrushes having electrically driven rotatable bristles are known. However, electric toothbrushes tend to be rather expensive to purchase. Furthermore, it has been observed that many people are generally hesitant about placing an electrically powered device in their mouths in the belief that it is potentially dangerous to do so. Manually operated toothbrushes thus remain by far the preferred means by which persons clean their teeth.
Prior attempts have been made to provide a manually operated toothbrush that can impart a rotary motion to its brush head and thus the bristles mounted thereon. However, a disadvantage associated with many of these devices is that two hands are often required to operate them. It has also been observed that the construction of many of these devices does not enable users to easily clean the rear molars. In particular, the size of the mouth and the construction of many of the devices prohibits lateral movement of the rotatable bristles across the crown of the rear molars. Furthermore, in many instances the bristles do not move in a circular motion over the surface of the teeth.
It is an object of the present invention to provide a toothbrush that overcomes at least one of the aforementioned disadvantages and which will be reliable and efficient in use.
With the foregoing and other objects in view this invention in one aspect resides in a manually operable toothbrush including:
a handle having drive means associated with one end thereof;
a housing that in use is locatable inside a user""s mouth and which is adapted to receive said drive means;
a tube connected to-said housing and through which said handle extends;
a bristle assembly that is capable of rotation relative to said housing, said bristle assembly having a driven portion that is retained within said housing and which is operatively connected to said drive means and wherein rotation of said bristle assembly is effected by reciprocal movement of said handle relative to said housing, and whereby in use a free end of said tube is always located outside the user""s mouth.
The housing may, in some embodiments, be capable of flexible movement relative to said handle. For example, the connection connecting the handle to the housing may be a flexible connection. Alternatively, the handle, or selected portions of the handle, may be constructed from a flexible material.
In addition to having a plurality of rotatable bristles, the housing may also include a plurality of bristles whose position relative to said housing are fixed. The bristles may be arranged according to a particular pattern. For example, the rotatable bristles may be surrounded by fixed bristles that extend along the periphery of the head portion. In addition, the length of the fixed bristles and the rotatable bristles may be the same or may differ. For example, in one embodiment the longer rotatable bristles may stand proud of the fixed bristles.
The drive means may consist of a rack and at least one mating pinion and wherein the rotatable bristles may be mounted on said pinion. In one embodiment, the rack may be connected to or formed integrally with the handle and wherein rotational movement of the bristles is effected by reciprocal movement of the handle towards and away from the housing. Alternatively the rack may consist of a driving member that is slidably mounted on the handle and wherein movement of the driving member may be effected using the user""s thumb.
The rack may also include motion dampening means, such as a tension or compression spring connected to and located intermediate one end of the rack and an opposing end of a separate driving member used to impart motion to the rack. The motion dampening means may be used to compound the extent of rotational movement of the bristles derived from movement of the driving member.
The drive means, or a significant portion of same, is preferably enclosed within the housing of the toothbrush thereby reducing the likelihood of saliva and food products becoming trapped within the drive means. For example, the rack like end portion of the handle and the mating pinions may be housed within a tubular housing. The housing preferably includes a closed end which is inserted in the user""s mouth and an opening at the other end through which the handle extends, and wherein the opening is never placed inside the user""s mouth during use.
The toothbrush may also include locking means that may be used to selectively prevent rotational movement of the bristles if desired. This may be particularly beneficial where movement of the bristles is effected by movement of the handle as it will also allow the user to use the toothbrush in a conventional manner.
In another aspect this invention resides in a toothbrush including:
a handle;
a head portion connected to said handle, said head portion having a plurality of bristles that are capable of rotation relative to said head portion about an axis that extends laterally from said handle;
drive means associated with said handle for manually driving said rotatable bristles, and
locking means that may be used to selectively disable said drive means.
For example the locking means may simply include a pin that is locatable within aligned apertures formed in the driving member and an adjacent portion of the head portion. When the pin is partially withdrawn such that it no longer engages one of the apertures, the driving member is free to move relative to the head portion. When the pin is removed entirely the driving member can be separated from the rest of the unit thereby enabling a thorough cleaning of the unit if so desired and, if necessary, the replacement of the head portion should the bristles be worn and/or splayed apart.
In another aspect this invention resides in a toothbrush including:
a handle;
a head portion connected to said handle, said head portion having a plurality of bristles that are capable of rotation relative to said head portion about an axis that extends laterally from said handle, and
drive means associated with said handle for manually driving said rotatable bristles, and wherein the portion of said drive means that in use is located inside a person""s mouth is housed within said head portion.
Preferably the arrangement of the drive means and the head portion is such that during use, little if any saliva and food products can become trapped inside the head portion amongst the drive means.
For example, the drive means may consist of a rack and at least one mating pinion and wherein the rotatable bristles may be mounted on said pinion. In one embodiment, the rack may be connected to or formed integrally with the handle and wherein rotational movement of the bristles is effected by reciprocal movement of the handle towards and away from the head portion. Alternatively the rack may consist of a driving member that is slidably mounted on the handle and wherein movement of the driving member may be effected using the user""s thumb.
The rack may also include motion dampening means, such as a tension or compression spring connected to and located intermediate one end of the rack and an opposing end of a separate driving member used to impart motion to the rack. The motion dampening means may be used to compound the extent of rotational movement of the bristles derived from movement of the driving member.
The rack like end portion of the handle and the mating pinions may be housed within a tubular housing that forms part of the head portion. The housing preferably includes a closed end which is inserted in the user""s mouth and an opening at the other end through which the handle extends, and wherein the opening is never placed inside the user""s mouth during use.